title: Forces driving the attachment of Staphylococcus epidermidis to fibrinogen-coated surfaces.
abstract: Cell surface proteins of bacteria play essential roles in mediating the attachment of pathogens to host tissues and, therefore, represent key targets for anti-adhesion therapy. In the opportunistic pathogen Staphylococcus epidermidis , the adhesion protein SdrG mediates attachment of bacteria to the blood plasma protein fibrinogen (Fg) through a binding mechanism that is not yet fully understood. We report the direct measurement of the forces driving the adhesion of S. epidermidis to Fg-coated substrates using single-cell force spectroscopy. We found that the S. epidermidis -Fg adhesion force is of ~150 pN magnitude and that the adhesion strength and adhesion probability strongly increase with the interaction time, suggesting that the adhesion process involves time-dependent conformational changes. Control experiments with mutant bacteria lacking SdrG and substrates coated with the Fg β(6-20) peptide, instead of the full Fg protein, demonstrate that these force signatures originate from the rupture of specific bonds between SdrG and its peptide ligand. Collectively, our results are consistent with a dynamic, multi-step ligand-binding mechanism called "dock, lock, and latch".
authors.affiliation: Institute of Life Sciences, Université catholique de Louvain , Croix du Sud 1, bte L7.04.01, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: Philippe
authors.initials: P
authors.lastname: Herman
authors.forename: Sofiane
authors.initials: S
authors.lastname: El-Kirat-Chatel
authors.forename: Audrey
authors.initials: A
authors.lastname: Beaussart
authors.forename: Joan A
authors.initials: JA
authors.lastname: Geoghegan
authors.forename: Thomas
authors.initials: T
authors.lastname: Vanzieleghem
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Foster
authors.forename: Pascal
authors.initials: P
authors.lastname: Hols
authors.forename: Jacques
authors.initials: J
authors.lastname: Mahillon
authors.forename: Yves F
authors.initials: YF
authors.lastname: Dufrêne
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D005340:Fibrinogen / Q000737:chemistry* / Q000378:metabolism*; D010316:Particle Size; D013212:Staphylococcus epidermidis / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism*; D013499:Surface Properties
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; C112556:Fbe protein, bacteria; D005340:Fibrinogen